1. Field of the Invention
The invention generally relates to an oscillator, in particular, to a RC oscillator.
2. Description of Related Art
Generally speaking, an oscillator may be applied to various electronic products for providing a required clock signal in the inner circuit of the electronic products.
In the electronic products nowadays, such as communication devices or mobile devices, for fitting the requirement of small volume, the oscillator is usually implemented in an integrated circuit to save the layout space of the devices. Wherein, the oscillator in the integrated circuit usually includes resistors and capacitors, and the periodic clock signal is generated by delay time through charging and discharging the resistors and the capacitors of the integrated circuit. However, the resistances in the integrated circuit easily alter following the change of temperature. Moreover, in a prior art, the oscillating frequency of the output signal of the RC oscillator is dependent on an operation voltage received by the RC oscillator. Therefore, in the condition that the operation voltage alters, the frequency of the output signal generated by the RC oscillator changes correspondingly and further the stability of a system having the RC oscillator is affected.